1. Field of the Invention
The present disclosure relates to an energy storage device, and more particularly, to an energy storage device having an improved heat-dissipation characteristic.
2. Description of Related Art
Generally, an ultra-capacitor is also called a super capacitor and serves as an energy storage device having characteristics in between an electrolytic condenser and a secondary battery. The ultra-capacitor is a next-generation electric energy storage device which may be used together with, or instead of, a secondary battery due to high efficiency and semi-permanent life span.
The ultra-capacitor is used as a substitute for a storage battery when an application is not easy to maintain and require a long-term life span. The ultra-capacitor has a rapid charge/discharge rate and thus may be used as an auxiliary power source of a cellular phone, a notebook, a PDA or the like, which is a mobile communication information device. In addition, the ultra-capacitor is very suitable as a main or auxiliary power source of an electric vehicle, a pilot lamp on the road, an uninterrupted power supply (UPS) or the like, which demands a high capacity.
When the ultra-capacitor is applied, a high-voltage module of several thousand Farad or several hundred bolts is required in order to use the ultra-capacitor as a high-voltage battery. The high-voltage module may be configured by connecting a required number of ultra-capacitors in a case.
FIG. 1 is a diagram showing an existing ultra-capacitor module.
As shown in FIG. 1, the existing ultra-capacitor module includes an ultra-capacitor array 10, a case 20 accommodating the ultra-capacitor array 10, and covers 30, 40 covering upper and lower openings of the case 20. The ultra-capacitor array 10 is configured by connecting electrode terminals of a plurality of ultra-capacitors by means of a bus bar 11 and coupling them by nuts.
The ultra-capacitor module may improve energy storage characteristics by operating a plurality of ultra-capacitors. However, the heat generated when operating the ultra-capacitor module also increases rapidly, which may deteriorate reliability or stability of the ultra-capacitor module.
The existing ultra-capacitor module as described above dissipates heat mainly through the bus bar 11 serving as a connection member connecting adjacent ultra-capacitors and the covers 30, 40 made of metal and covering upper and lower surfaces of the case 20. However, a side of the case 20 is made of a synthetic resin in order to reduce a weight of the ultra-capacitor module and lower a production cost thereof. In addition, the side of the case 20 has a plate shape, and thus a contact area with the ultra-capacitor is small and thus does not substantially dissipate heat.
In addition, in the existing technique, the ultra-capacitor may mainly dissipate heat through the bus bar 11, but the bus bar 11 is not able to efficiently dissipate heat due to a small heat-dissipating area. Thus, due to the increased temperature in the case, the life span of the ultra-capacitor may be reduced.
(Patent Literature 1) Korean Patent Registration No. 10-1341474 (published on Dec. 13, 2013)